1897.] Fossils and Fossilization. 33 
occasion to call attention, in the collection of Dr. Clapp,’ to the 
equal perfection of the “ pores, foramina and minute micro- 
scopic structure” of the palaeozoic corals with those gathered 
from our present oceans, remarking that “no one but a zoolo- 
gist would have been able to guess which set were of modern, 
and which of ancient, origin.” 
We may feel quite confident that in any study of our fossil- 
bearing strata we are generally contemplating beds that have 
not been abyssal in their origin. The remains of mollusca in 
the abundance usually present in our fossiliferous beds, cannot 
easily be regarded as indicative of very great depths of deposi- 
tion. The Challenger expedition, while it revealed an unex- 
pected fertility in the deep-sea life, also showed that molluscan 
life at great depths was scanty and unimportant. Sir C. 
Wyville Thompson summarizes the conclusions reached by say- 
ing that “the two great modern groups of the mollusca, the 
Lamellibranchiata and the Gastropoda, do not enter largely 
into the fauna of the deep sea. Species of both groups, usually 
small and apparently stunted, were widely, though sparsely, 
diffused.” The character of many of the fossiliferous beds be- 
trays readily enough the bathymetric relations they bore to 
the continent. The sandy grits, coarse conglomerate, the 
shales and slates, modified by the calcareous debris of shells 
and the argillaceous marls, are not deep-sea products. The 
pure limestones themselves cannot be regarded as having been 
formed at excessive depths since so much of the ancient life 
preserved in their fossils is irreconcilable with this view. Prof. 
A. Agassiz has indeed written (Dredgings of Three Cruises of 
the Blake): “ Probably no invertebrates of a period older than 
the jura and chalk existed in the deep sea, or, if they did exist, 
they did not wander far from the continental shelf. Their 
distribution was then as to-day, mainly a question of food. 
The animals of those times lived upon the shelf, and, while 
they and their predecessors remained as fossils in the littoral 
beds of the earlier formations, their successors, belonging 
either to the same or to allied genera, passed over into the fol- 
lowing period.” 
3 Second Visit to the United States: Sir Chas. Lyell. 
3 (To be continued.) 
